Internally threaded fasteners are used in numerous applications for fastening joints. A common embodiment of such a fastener is the hex nut, which can be coupled to an externally threaded male fastener portion, such as to affix an appurtenance onto a structure using compressive force generated by tightening the nut against the appurtenance. Often, the appurtenance to be attached has mounting holes, bores, or sleeves to accommodate the externally threaded male fastener portion. A spacer between the appurtenance and structure is sometimes required to create a stand-off, such as when excessive heat or vibration is a concern. Sometimes the male fastener portion is placed through a sleeve, which can act as a crush limiter when the appurtenance to be attached includes compressible materials such as rubber or plastic.
One disadvantage to internally threaded fasteners known to the art is that such fasteners must be aligned precisely with a male fastener portion to properly engage the threads. Such precise alignment can be difficult to achieve. Misalignment can cause the internally threaded fastener to fail prematurely or to exert insufficient clamping force after installation. To ensure proper alignment, internally threaded fasteners are generally started onto the male fastener portion by hand, which is a slow process. Further, fasteners known to the art often require the use of washers to provide stability. Since such washers are separate from the internally threaded fastener and the male fastener portion, they can easily become lost prior to or during installation, or if the internally threaded fastener fails or becomes cracked. Additionally, fasteners known to the art depend on the structural integrity of the internally threaded fastener to secure the connection. Should the internally threaded fastener crack or break, a connection secured by fasteners known to the art will fail.
There is a need in the art for an internally threaded fastener that self-aligns with a male fastener portion, increasing the speed of installation and decreasing the risk of mis-threading, cross-threading, insufficient clamping force, or premature connection failure. Embodiments of the present invention satisfy many of these needs. There is, further, a need in the art for fasteners that decrease the problems associated with separate washers and that provide a fail-safe means of connection if the internally threaded fastener fails. Embodiments of the present invention satisfy these needs. There is, further, a need in the art for fasteners that can retain connection with a male fastener member even if the internally threaded fastener cracks or breaks. Embodiments of the present invention satisfy these needs.